Abstract:
The study investigates on sea surface temperature (SST) seasonal to interannual variability in the western Black Sea using gridded fields of MODIS derived SST monthly averages of 4 km horizontal resolution. More specifically, winter and summer SSTs products were considered spanning a 17-year period (2003-2019).To this end, seasonal climatic mean fields were obtained and observed features were discussed from a hydrodynamic view point. Furthermore, time series of winter and summer SST means were analysed to reveal the spatial variability pattern. In terms of zonal flow, the winter SST increases eastward, while the summer ones – from northwest to southeast. Both winter and summer SSTs exhibit increasing long-term trends; there is almost uniform increase of the winter SSTs of 0.6-0.7°C per decade for all zonal areas, while the summer ones tend to vary in somewhat wider range – 0.5-0.7°C per decade. Besides, based on the normalized SST anomalies, it was found out that during 2003-2019 SSTs have grown with a lower rate compared to the two preceding decades. Finally, in attempt to link the SST variability to global teleconnection patterns such as North Atlantic Oscillation (NAO), a spectral analysis of seasonal time series was performed, which indicated the existence of quasi-decadal scale of variation that roughly follows the NAO positive and negative cycles.